Air conditioner

ABSTRACT

An air conditioner may include: an outdoor unit including a compressor and an outdoor heat exchanger; a first indoor unit including a first indoor heat exchanger; and a second indoor unit including a second indoor heat exchanger and an indoor expansion valve, wherein the outdoor unit includes: a first outdoor pipe, an outdoor expansion valve provided in the first outdoor pipe, the first outdoor pipe allowing a refrigerant discharged from the outdoor heat exchanger to pass through the outdoor expansion valve and flow to the first indoor unit; and a second outdoor pipe allowing a refrigerant discharged from the outdoor heat exchanger to bypass the outdoor expansion valve and flow to the second indoor unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application, under 35 U.S.C. § 111(a), of International Patent Application No. PCT/KR2022/010976, filed on Jul. 26, 2022, which claims the benefit of Korean Patent Application No. 10-2021-0158489, filed Nov. 17, 2021, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference as a part of this application.

BACKGROUND Field

The disclosure relates to an air conditioner having an improved refrigerant pipe structure.

Description of Related Art

In general, an air conditioner, as an apparatus for providing comfortable indoor air, may control temperature, humidity, and air current distribution to be suitable for human activities of an indoor space and also eliminate dust from air. In general, the air conditioner includes a refrigeration cycle including a compressor, a condenser, an expansion device, and an evaporator, and may perform a cooling or heating operation according to a circulation direction of a refrigerant.

The air conditioner is generally configured such that one indoor unit is connected to one outdoor unit, hut recently, there is an increasing demand for a multi-type air conditioner in which several indoor units having various shapes and capacities are connected to one outdoor unit.

Such a multi-type air conditioner may be divided into a single pipe structure and a multi-pipe structure according to the shape of the refrigerant pipe. The single pipe structure is a structure in which a single main pipe is provided from an outdoor unit, and sub pipes from the single main pipe are connected to respective indoor units through a branch device. The multi-pipe structure is a structure in which each indoor unit is connected to an outdoor unit through a separate pipe. For example, a commercial indoor unit having a built-in expansion valve may be installed in a single-pipe structure, and a household indoor unit not having a built-in expansion valve may be installed in a multi-pipe structure. The single pipe structure air conditioner may be used in a commercial area, and the multi pipe structure air conditioner may be used in a residential area.

However, since a single-pipe structure air conditioner and a multi-pipe structure air conditioner are not compatible with each other, when an indoor unit is additionally installed or the type of an indoor unit is changed, a separate connection part may be required or the outdoor unit may need to be changed. Accordingly, the pipe connection may become long and complicated.

In addition, as residential areas and commercial areas are mixed in recent years, there is a need for a pipe structure in which a single-pipe structure and a multi-pipe structure are integrated.

SUMMARY

According to an aspect of the disclosure, there is provided an air conditioner including: an outdoor unit including a compressor and an outdoor heat exchanger a first indoor unit including a first indoor heat exchanger; and a second indoor unit including a second indoor heat exchanger and an indoor expansion valve, wherein the outdoor unit includes: an outdoor expansion valve; a first outdoor pipe provided with the outdoor expansion valve, the first outdoor pipe allowing a refrigerant discharged from the outdoor heat exchanger to pass through the outdoor expansion valve and flow to the first indoor unit; and a second outdoor pipe allowing a refrigerant discharged from the outdoor heat exchanger to bypass the outdoor expansion valve and flow to the second indoor unit.

The air conditioner may further include: a first connection pipe connecting the outdoor unit to the first indoor unit by connecting to the first outdoor pipe of the outdoor unit; and a second connection pipe connecting the outdoor unit to the second indoor unit by connecting to the second outdoor pipe of the outdoor unit.

The outdoor unit may further include: a first connection valve connecting the first outdoor pipe to the first connection pipe; and a second connection valve connecting the second outdoor pipe to the second connection pipe.

The refrigerant passing through the outdoor expansion valve may pass through the first connection valve and the first connection pipe and then flow into the first indoor heat exchanger, and the refrigerant bypassing the outdoor expansion valve may pass through the second connection valve and the second connection pipe and then flow into the indoor expansion valve.

The air conditioner may further comprise a plurality of first indoor units, the plurality of first indoor units including the first indoor unit; a plurality of first outdoor pipes, the plurality of first outdoor pipes including the first outdoor pipe; a plurality of first connection valves, the plurality of first connection valves including the first connection valve; and a plurality of first connection pipes, the plurality of first connection pipes including the first connection pipe; the plurality of first outdoor pipes, the plurality of first connection valves, and the plurality of first connection pipes may be respectively connected in series to form a plurality of refrigerant lines, and each of the plurality of first indoor units may correspond to a respective one of the plurality of refrigerant lines to be connected to the outdoor heat exchanger.

The air conditioner may further comprise a plurality of second indoor units, the plurality of second indoor units including the second indoor unit, and the second connection pipe may include: a main connection pipe provided to be connected to the second connection valve; and a plurality of sub connection pipes branched from the main connection pipe and each of the plurality of sub connection pipes corresponding to a respective one of the plurality of second indoor units.

The first connection valve has at least one of a shape, a form, a size, and a color different from those of the second connection valve so that the first connection valve and the second connection valve are visually identifiable from each other.

The outdoor unit may further include a valve marker configured to indicate a connection state of the first connection valve and the second connection valve.

The outdoor unit may further include an outdoor unit communicator to communicate with the first indoor unit and the second indoor unit, the outdoor unit communicator configured to receive information on whether the first indoor unit includes an indoor expansion valve and information on whether the second indoor unit includes an indoor expansion valve.

The air conditioner may further include a controller configured to control the valve marker based on the information received from the outdoor unit communicator.

The air conditioner may further include: a third connection pipe connecting the first indoor unit to the outdoor unit such that a refrigerant discharged from the first indoor unit is introduced into the outdoor unit; and a fourth connection pipe connecting the second indoor unit to the outdoor unit such that a refrigerant discharged from the second indoor unit is introduced into the outdoor unit.

The outdoor unit may further include: a third outdoor pipe through which the refrigerant flowing through the third connection pipe is introduced; and a fourth outdoor pipe through which the refrigerant flowing through the fourth connection pipe is introduced, wherein the third outdoor pipe and the fourth outdoor pipe may be provided to join before being introduced into the compressor.

The outdoor unit may further include: a third connection valve connecting the third outdoor pipe to the third connection pipe; and a fourth connection valve connecting the fourth outdoor pipe to the fourth connection pipe.

The third connection valve has at least one of a shape, a form, a size, and a color different from those of the fourth connection valve so that the third connection valve and the fourth connection valve may be visually identifiable from each other.

The air conditioner may further include a four-way valve configured to switch a flow path such that a refrigerant compressed by the compressor selectively flows to the outdoor heat exchanger or to the first indoor heat exchanger and the second indoor heat exchanger.

An air conditioner including: an outdoor unit including a compressor and an outdoor heat exchanger; a first indoor unit including a first indoor heat exchanger; a second indoor unit including a second indoor heat exchanger; a first pipe connecting the outdoor heat exchanger to the first indoor heat exchanger; a second pipe connecting the outdoor heat exchanger to the second indoor heat exchanger, an outdoor expansion valve provided inside the outdoor unit, the outdoor expansion valve disposed on one side of the first indoor heat exchanger on the first pipe and configured to expand a refrigerant under reduced pressure, an indoor expansion valve provided inside the second indoor unit, the indoor expansion valve disposed on one side of the second indoor heat exchanger on the second pipe and configured to expand a refrigerant under reduced pressure; a first connection valve disposed between the outdoor expansion valve and the first indoor heat exchanger to control the amount of refrigerant flowing through the first pipe; and a second connection valve disposed between the first connection valve and the outdoor heat exchanger to control the amount of refrigerant flowing through the second pipe;

The first connection valve and the second connection valve may be provided to be mutually identifiable from each other.

A portion of the refrigerant discharged from the outdoor heat exchanger may pass through the outdoor expansion valve to be supplied to the first indoor heat exchanger via, and the remaining of the refrigerant discharged from the outdoor heat exchanger may bypass the outdoor expansion valve to be supplied to the indoor expansion valve.

The outdoor heat exchanger may be provided to condense the refrigerant, and the first indoor heat exchanger and the second indoor heat exchanger may be provided to evaporate the refrigerant.

Each of the first indoor unit and the second indoor unit may be provided in plural.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating an air conditioner according to an embodiment.

FIG. 2 is a schematic diagram illustrating an air conditioner according to an embodiment.

FIG. 3 is a schematic diagram illustrating an air conditioner according to an embodiment.

FIG. 4 is a schematic diagram illustrating an air conditioner according to an embodiment.

FIG. 5 is a diagram schematically illustrating a cooling operation mode of the air conditioner shown in FIG. 1 .

FIG. 6 is a diagram schematically illustrating a heating operation mode of the air conditioner shown in FIG. 1 .

FIG. 7 is a control block diagram illustrating an air conditioner according to an embodiment.

DETAILED DESCRIPTION

Embodiments described in the specification and configurations shown in the accompanying drawings are merely examples of the present disclosure, and various modifications may replace the embodiments and the drawings of the present disclosure.

Further, identical symbols or numbers in the drawings of the present disclosure denote components or elements configured to perform substantially identical functions.

Further, terms used herein are only for the purpose of describing particular embodiments and are not intended to limit to the present disclosure. The singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It need to be further understood that the terms “include,” “including,” “have,” and/or “having” specify the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

When a part is referred to as being “connected to” another part, it may not only be directly connected to the other part but may also be indirectly connected to the other part. Similarly, when a part is referred to as being “coupled to” another part, it may not only be directly coupled to the other part but may also be indirectly coupled to the other part. Similarly,

In the description of an embodiment, it will be understood that, when a layer is referred to as being “on/under” another layer or substrate, it may be directly on/under the other layer or substrate, or one or more intervening layers may also be present.

Further, it need to be understood that, although the terms “first,” “second,” etc. may be used herein to describe various elements, the elements are not limited by the terms, and the terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element without departing from the scope of the present disclosure. The term “and/or” includes combinations of one or all of a plurality of associated listed items.

Hereinafter, an embodiment according to the disclosure will be described in detail with reference to the accompanying drawings.

An air conditioner 1 may include an outdoor unit 10 and at least one indoor unit 20 and 30, The air conditioner 1 may include an outdoor unit 10, a first indoor unit 20 not including an indoor expansion valve, and a second indoor unit 30 including an indoor expansion valve 38. In the drawings, the outdoor unit 10 is illustrated as one outdoor unit, but the outdoor unit 10 may be provided as a plurality of outdoor units to which at least one indoor unit 20 and 30 is connected.

Hereinafter, embodiments according to the disclosure will be described with reference to FIGS. 1 to 4 . For the sake of convenience of description, the description of FIGS. 1 to 4 will be made in relation to a cooling operation mode of the air conditioner 1 unless otherwise stated.

Referring to FIG. 1 , the air conditioner 1 may include the outdoor unit 10, the first indoor unit 20, and the second indoor unit 30. In FIG. 1 , the first indoor unit 20 and the second indoor unit 30 are each illustrated as one indoor unit, but the disclosure is not limited thereto. At least one first indoor unit 20 may be provided. At least one second indoor unit 30 may be provided.

The air conditioner 1 may include a connection pipe 40 connecting the outdoor unit 10 to the indoor units 20 and 30.

The outdoor unit 10 may include a compressor 15, an outdoor heat exchanger 11, a fan motor 12, an outdoor fan 13, and a refrigerant pipe P1.

The compressor 15 may compress a refrigerant. For example, the compressor 15 may compress a refrigerant in a low-temperature and low-pressure gas state sucked through a suction side 15 a and discharge a refrigerant in a high-temperature and high-pressure gas state through a discharge side 15 b.

The outdoor heat exchanger 11 may be provided outdoors to perform heat exchange between outdoor air and a refrigerant. The outdoor heat exchanger 11 is provided as a condenser for condensing a refrigerant in a cooling operation mode, and as an evaporator for evaporating a refrigerant in a heating operation mode.

The outdoor fan 13 may forcibly blow the outdoor air so that heat exchange between the outdoor air and the refrigerant is performed in the outdoor heat exchanger 11. The outdoor fan 13 may be driven by the fan motor 12.

The outdoor unit 10 may include an accumulator 14. The accumulator 14 may be provided on the suction side 15 a of the compressor 15 to separate the refrigerant into a liquid and a gas. The accumulator 14 may convert the refrigerant sucked into the compressor 15 into a gas in a perfect gaseous state.

A four-way valve 16 may switch a flow path so that the refrigerant compressed by the compressor 15 flows to the outdoor heat exchanger 11 or indoor heat exchangers 21 and 31. The four-way valve 16 may be switched to change the flow of a refrigerant according to an operation mode (a cooling operation mode or a heating operation mode) selected by the user.

The four-way valve 16 may include a first port 161, a second port 162, a third port 163, and a fourth port 164.

The first port 161 may be connected to the compressor 15. The first port 161 may be connected to the suction side 15 a of the compressor 15 through a refrigerant pipe 186. The second port 162 may be connected to the compressor 15. The second port 162 may be connected to the discharge side 15 b of the compressor 15 through a refrigerant pipe 187. The third port 163 may be connected to the indoor units 20 and 30 through refrigerant pipes 185, 183, and 184. The fourth port 164 may be connected to the outdoor heat exchanger 11. The fourth port 164 may, be connected to the outdoor heat exchanger 11 through a refrigerant pipe 188.

The outdoor expansion valve 17 may expand the refrigerant under reduced pressure. For example, the outdoor expansion valve 17 may be an electronic expansion valve (EEV) capable of adjusting the flow rate of a refrigerant. The EEV may control the flow rate of a refrigerant by adjusting the opening degree.

The refrigerant pipe P1 of the outdoor unit 10 may include one or more refrigerant pipes 180, 181, 182, 183, 184, 185, 186, 187, and 188.

The refrigerant pipe 180 may be provided on one side of the outdoor heat exchanger 11. For example, in a cooling mode, the refrigerant pipe 180 may be a pipe provided on a downstream side of the outdoor heat exchanger 11 and through which a refrigerant discharged from the outdoor heat exchanger 11 flows. For example, in a heating operation mode, the refrigerant pipe 180 may be a pipe provided on an upstream side of the outdoor heat exchanger 11 and through which a refrigerant sucked into the outdoor heat exchanger 11 flows.

The first outdoor pipe 181 and the second outdoor pipe 182 may be branched from the refrigerant pipe 180.

The first outdoor pipe 181 may have an outdoor expansion valve 17 disposed thereon. The first outdoor pipe 181 may allow the refrigerant discharged from the outdoor heat exchanger 11 to pass through the outdoor expansion valve 17 and flow to the first indoor unit 20.

The second outdoor pipe 182 may not have an outdoor expansion valve 17 disposed thereon. The second outdoor pipe 182 may allow the refrigerant discharged from the outdoor heat exchanger 11 to bypass the outdoor expansion valve 17 and flow to the second indoor unit 30.

The refrigerant discharged from the first indoor unit 20 may flow into the third outdoor pipe 183. The refrigerant discharged from the second indoor unit 30 may flow into the fourth outdoor pipe 184.

The third outdoor pipe 183 and the fourth outdoor pipe 184 may be provided to join before being introduced into the compressor 15. For example, the third outdoor pipe 183 and the fourth outdoor pipe 184 may join before being introduced into the third port 163 of the four-way valve 16 to form the refrigerant pipe 185.

The refrigerant pipe 185 may be provided on one side of the compressor 15. The refrigerant pipe 185 may be provided to be connected to the third port 163 of the four-way valve 16. The refrigerant pipe 185 may be connected to the third outdoor pipe 183 and the fourth outdoor pipe 184. For example, in a cooling mode, the refrigerant pipe 185 may be a pipe provided on an upstream side of the compressor 15 and through which the refrigerant discharged from the indoor units 20 and 30 flows. For example, in a heating operation mode, the refrigerant pipe 185 may be a pipe provided on a downstream side of the compressor 15 and through which the refrigerant discharged from the compressor 15 flows.

The refrigerant pipe 186 may connect the four-way valve 16 to the compressor 15. The refrigerant pipe 186 may connect the first port 161 of the four-way valve 16 to the suction side 15 a of the compressor 15.

The refrigerant pipe 187 may connect the four-way valve 16 to the compressor 15. The refrigerant pipe 187 may connect the second port 162 of the four-way valve 16 to the discharge side 15 b of the compressor 15.

The refrigerant pipe 188 may connect the outdoor heat exchanger 11 to the fourth port 164 of the four-way valve 16. The refrigerant pipe 188 may be a pipe through which a refrigerant flows between the outdoor heat exchanger 11 and the compressor 15.

The outdoor unit 10 may include a first connection valve 110 and a second connection valve 120. The first connection valve 110 may connect the first outdoor pipe 181 to a first connection pipe 41 to be described below. The second connection valve 120 may connect the second outdoor pipe 182 to a second connection pipe 42 to be described below.

For example, in a cooling operation mode, the first connection valve 110 and the second connection valve 120 may control the amount of refrigerant discharged from the outdoor heat exchanger 11. In this case, the first connection valve 110 and the second connection valve 120 may be referred to as exit valves of the outdoor unit 10.

For example, in a heating operation mode, the first connection valve 110 and the second connection valve 120 may control the amounts of refrigerant introduced from the first indoor unit 20 and the second indoor unit 30, respectively. In this case, the first connection valve 110 and the second connection valve 120 may be referred to as entry valves of the outdoor unit 10.

The outdoor unit 10 may include a third connection valve 130 and a fourth connection valve 140. The third connection valve 130 may connect the third outdoor pipe 183 to a third connection pipe 43 to be described below. The fourth connection valve 140 may connect the fourth outdoor pipe 184 to a fourth connection pipe 44 to be described below.

For example, in a cooling operation mode, the third connection valve 130 and the fourth connection valve 140 may control the amounts of refrigerant introduced from the first indoor unit 20 and the second indoor unit 30, respectively. In this case, the third connection valve 130 and the fourth connection valve 140 may be referred to as entry valves of the outdoor unit 10.

For example, in a heating operation mode, the third connection valve 130 and the fourth connection valve 140 may control the amount of refrigerant discharged from the compressor 15. In this case, the third connection valve 130 and the fourth connection valve 140 may be referred to as exit valves of the outdoor unit 10.

The first indoor unit 20 may be an indoor unit not having an indoor expansion valve. For example, the first indoor unit 20 may include a household indoor unit in which an indoor expansion valve is not built-in. When considering that a household indoor unit is generally installed in a residential space, the household indoor unit may not be provided with an indoor expansion valve to prevent an influence of noise generated during a reduced-pressure expansion process of a refrigerant.

The first indoor unit 20 may include the first indoor heat exchanger 21. The first indoor heat exchanger 21 may be provided indoors to perform heat exchange between indoor air and a refrigerant. The first indoor heat exchanger 21 may be provided as an evaporator for evaporating a refrigerant in a cooling operation mode, and may be provided as a condenser for condensing a refrigerant in a heating operation mode.

The first indoor unit 20 may include a fan motor 22 and an indoor fan 23 (see FIG. 7 ). The indoor fan 23 may forcibly blow indoor air so that heat exchange between the indoor air and the refrigerant is performed in the first indoor heat exchanger 21. The indoor fan 23 may be driven by the fan motor 22.

The first indoor unit 20 may include a refrigerant pipe P2, i.e., 24 and 25. The refrigerant pipe P2 of the first indoor unit 20 may be provided as a plurality of refrigerant pipes 24 and 25.

The refrigerant pipe 24 may be provided at a first side of the first indoor heat exchanger 21, and the refrigerant pipe 25 may be provided at a second side of the first indoor heat exchanger 21.

For example, in a cooling operation mode, the refrigerant pipe 24 may be provided on an upstream side of the first indoor heat exchanger 21, and the refrigerant pipe 25 may be provided on a downstream side of the first indoor heat exchanger 21.

For example, in a heating operation mode, the refrigerant pipe 24 may be provided on a downstream side of the first indoor heat exchanger 21, and the refrigerant pipe 25 may be provided on an upstream side of the first indoor heat exchanger 21.

The first indoor unit 20 may include connection valves 26 and 27. The connection valves 26 and 27 of the first indoor unit 20 may be provided in plural.

The connection valve 26 may connect the first connection pipe 41, which will be described below, to the refrigerant pipe 24. The connection valve 27 may connect the third connection pipe 43, which will be described below, to the refrigerant pipe 25.

For example, in a cooling operation mode, the connection valve 26 may control the amount of refrigerant introduced from the outdoor unit 10. In this case, the connection valve 26 may be referred to as an entry valve of the first indoor unit 20. For example, in a heating operation mode, the connection valve 26 may control the amount of refrigerant discharged from the first indoor unit 20. In this case, the connection valve 26 may be referred to as an exit valve of the first indoor unit 20.

For example, in a cooling operation mode, the connection valve 27 may control the amount of refrigerant discharged from the first indoor unit 20. In this case, the connection valve 27 may be referred to as an exit valve of the first indoor unit 20. For example, in a heating operation mode, the connection valve 27 may control the amount of refrigerant introduced from the outdoor unit 10. In this case, the connection valve 27 may be referred to as an entry valve of the first indoor unit 20.

The second indoor unit 30 may be an indoor unit provided with an indoor expansion valve 38. For example, the second indoor unit 30 may include a commercial indoor unit in which the indoor expansion valve 38 is built-in. In general, since a commercial indoor unit includes a pipe between the outdoor unit and the indoor unit having a length longer than that of a household indoor unit, an expansion valve may be provided in the indoor unit to compensate for a pressure loss due to the long pipe.

The indoor expansion valve 38 may expand the refrigerant under reduced pressure. For example, the indoor expansion valve 38 may be an electronic expansion valve (EEV) capable of adjusting the flow rate of a refrigerant. The EEV may control the flow rate of the refrigerant by adjusting the opening degree.

The second indoor unit 30 may include a second indoor heat exchanger 31. The second indoor heat exchanger 31 may be provided indoors to perform heat exchange between indoor air and a refrigerant. The second indoor heat exchanger 31 may be provided as an evaporator for evaporating a refrigerant in a cooling operation mode, and may be provided as a condenser for condensing a refrigerant in a heating operation mode.

The second indoor unit 30 may include a fan motor 32 and an indoor fan 33 (see FIG. 7 ). The indoor fan 33 may force the indoor air to be blown so that heat exchange between the indoor air and the refrigerant is performed in the second indoor heat exchanger 31. The indoor fan 33 may be driven by the fan motor 32.

The second indoor unit 30 may include a refrigerant pipe P3, i.e., 34 and 35, The refrigerant pipe P3 may be provided as a plurality of refrigerant pipes 34 and 35.

The second indoor unit 30 may include a refrigerant pipe P3, i.e., 34 and 35. The refrigerant pipe P2 of the second indoor unit 30 may be provided as a plurality of indoor units 34 and 35.

The refrigerant pipe 34 may be provided on a first side of the second indoor heat exchanger 31, and the refrigerant pipe 35 may be provided on a second side of the second indoor heat exchanger 31.

For example, in a cooling operation mode, the refrigerant pipe 34 may be provided on an upstream side of the second indoor heat exchanger 31, and the refrigerant pipe 35 may be provided on a downstream side of the second indoor heat exchanger 31.

For example, in a heating operation mode, the refrigerant pipe 34 may be provided on a downstream side of the second indoor heat exchanger 31, and the refrigerant pipe 35 may be provided on an upstream side of the second indoor heat exchanger 31.

The indoor expansion valve 38 of the second indoor unit 30 may be disposed in the refrigerant pipe 34. For example, the refrigerant discharged from the outdoor heat exchanger 11 and bypassing the outdoor expansion valve 17 may pass through the indoor expansion valve 38 and flow into the second indoor heat exchanger 31.

The second indoor unit 30 may include connection valves 36 and 37. The connection valves 36 and 37 of the second indoor unit 30 may be provided in plural.

The connection valve 36 may connect the second connection pipe 42, which will be described below, to the refrigerant pipe 34. The connection valve 37 may connect the fourth connection pipe 44, which will be described below, to the refrigerant pipe 35.

For example, in a cooling operation mode, the connection valve 36 may adjust the amount of refrigerant introduced from the outdoor unit 10. In this case, the connection valve 36 may be referred to as an entry valve of the second indoor unit 30. For example, in a heating operation mode, the connection valve 36 may adjust the amount of refrigerant discharged from the second indoor unit 30. In this case, the connection valve 36 may be referred to as an exit valve of the second indoor unit 30.

For example, in a cooling operation mode, the connection valve 37 may adjust the amount of refrigerant discharged from the second indoor unit 30. In this case, the connection valve 37 may be referred to as an exit valve of the second indoor unit 30. For example, in a heating operation mode, the connection valve 37 may adjust the amount of refrigerant introduced from the outdoor unit 10. In this case, the connection valve 37 may be referred to as an entry valve of the second indoor unit 30.

The connection pipe 40 may connect the outdoor unit 10 to the indoor units 20 and 30.

For example, the connection pipe 40 may include the first connection pipe 41, the second connection pipe 42, the third connection pipe 43, and the fourth connection pipe 44.

Each of the first connection pipe 41 and the third connection pipe 43 may be provided to connect the outdoor unit 10 to the first indoor unit 20. Each of the second connection pipe 42 and the fourth connection pipe 44 may be provided to connect the outdoor unit 10 to the second indoor unit 30.

The first connection pipe 41 may connect the first outdoor pipe 181 of the outdoor unit 10 to the refrigerant pipe 24 of the first indoor unit 20. The first connection valve 110 of the outdoor unit 10 may connect the first outdoor pipe 181 to the first connection pipe 41. The connection valve 26 of the first indoor unit 20 may connect the first connection pipe 41 to the refrigerant pipe 24.

The first connection pipe 41 may connect the first outdoor pipe 181 provided with the outdoor expansion valve 17 to the first indoor unit 20 not provided with an indoor expansion valve.

The second connection pipe 42 may connect the second outdoor pipe 182 of the outdoor unit 10 to the refrigerant pipe 34 of the second indoor unit 30. The second connection valve 120 of the outdoor unit 10 may connect the second outdoor pipe 182 to the second connection pipe 42. The connection valve 36 of the second indoor unit 30 may connect the second connection pipe 42 to the refrigerant pipe 34.

The second connection pipe 42 may connect the second outdoor pipe 182 not provided with an outdoor expansion valve to the second indoor unit 30 provided with the indoor expansion valve 38.

The third connection pipe 43 may connect the refrigerant pipe 25 of the first indoor unit 20 to the third outdoor pipe 183 of the outdoor unit 10. The third connection valve 130 of the outdoor unit 10 may connect the third connection pipe 43 to the third outdoor pipe 183. The connection valve 27 of the first indoor unit 20 may connect the refrigerant pipe 25 to the third connection pipe 43.

The fourth connection pipe 44 may connect the refrigerant pipe 35 of the second indoor unit 30 to the fourth outdoor pipe 184 of the outdoor unit 10. The fourth connection valve 140 of the outdoor unit 10 may connect the fourth connection pipe 44 to the fourth outdoor pipe 184. The connection valve 37 of the second indoor unit 30 may connect the refrigerant pipe 35 to the fourth connection pipe 44.

The refrigerant pipe P1 of the outdoor unit 10, the refrigerant pipe P2 of the first indoor unit 20, the refrigerant pipe P3 of the second indoor unit 30, and the connection pipe 40 may form a refrigerant cycle in which a refrigerant circulates. The refrigerant cycle may be provided as a closed loop.

As described above, both the indoor unit 20 not provided with an indoor expansion valve and the indoor unit 30 provided with an indoor expansion valve may be connected to the outdoor unit 10. That is, the air conditioner 1 may implement both a single-pipe structure and a multi-pipe structure.

In general, an air conditioner may be provided in a single pipe structure or a multi-pipe structure. The single pipe structure is a structure in which an outdoor unit not having an outdoor expansion valve is connected through a branch pipe to indoor units (e.g., a commercial indoor unit) having indoor expansion valves. The multi-pipe structure is a structure in which an outdoor unit having an outdoor expansion valve is connected to indoor units (e.g., a residential indoor unit), which do not have indoor expansion valves, through separate pipes. For example, an air conditioner having a single pipe structure may be used in a commercial area, and an air conditioner having a multi pipe structure may be used in a residential area.

Recently, as commercial areas and residential areas are mixed, there is a need for a technology capable of installing both an indoor unit with built-in indoor expansion valve (e.g., a commercial indoor unit) and an indoor unit without a built-in indoor expansion valve (e.g., a residential indoor unit). However, since the air conditioner having a single pipe structure and the air conditioner having a multi pipe structure have different internal configurations and pipe designs, it is difficult to implement the air conditioners as a single system, and separate parts and the like are required. For example, when a household indoor unit without a built-in expansion valve needs to be additionally installed in an air conditioner having a single pipe structure, a separate distribution device having an expansion valve may be required. Accordingly, a space for installing separate parts and the like needs to be secured, and piping design may become very complicated to connect the separate parts and the like.

The disclosed air conditioner 1 may implement both a single-pipe structure and a multi-pipe structure through a simple piping design.

The outdoor unit 10 of the air conditioner 1 may include the first outdoor pipe 181 in which the outdoor expansion valve 17 is provided and the second outdoor pipe 182 in which the outdoor expansion valve 17 is not provided. The first indoor unit 20 may be connected to the first outdoor pipe 181 through the first connection pipe 41, and the second indoor unit 30 may be connected to the second outdoor pipe 182 through the second connection pipe 42. Accordingly, both the first indoor unit 20 not having a built-in indoor expansion valve and the second indoor unit 30 having a built-in indoor expansion valve may be connectable to the outdoor unit 10.

The refrigerant discharged from the outdoor heat exchanger 11 may pass through the refrigerant pipe 180 and branch into the first outdoor pipe 181 and the second outdoor pipe 182.

The refrigerant introduced into the first outdoor pipe 181 may pass through the outdoor expansion valve 17, and then through the first connection pipe 41, flow into the first indoor heat exchanger 21 of the first indoor unit 20. The refrigerant flowing into the first indoor heat exchanger 21 may be a refrigerant expanded under reduced pressure via the outdoor expansion valve 17.

The refrigerant introduced into the second outdoor pipe 182 may not pass through the outdoor expansion valve 17, but pass through the second connection pipe 42, flowing into the indoor expansion valve 38 of the second indoor unit 30. The refrigerant expanded under reduced pressure through the indoor expansion valve 38 may be introduced into the second indoor heat exchanger 31.

With such a configuration, both an indoor unit having an indoor expansion valve (e.g., a commercial indoor unit) and an indoor unit not having an indoor expansion valve (e.g., a residential indoor unit) may be installable in the outdoor unit 10. That is, both the first indoor unit and the second indoor unit of different types may be connectable to the outdoor unit regardless of whether the indoor unit has an indoor expansion valve (e.g., an EEV) built-in. Accordingly, the air conditioner 1 may implement one system in which a single pipe structure and a multi-pipe structure are integrated. In addition, since the air conditioner 1 does not require a separate component (e.g., a distribution device), installation restrictions may be eliminated and piping design may be simplified.

Meanwhile, the first connection valve 110 and the second connection valve 120 of the air conditioner 1 may be provided to be identifiable from each other. Accordingly, it is possible to prevent in advance an accident, such as an operator erroneously connecting the first indoor unit 20 and the second indoor unit 30 to the outdoor unit. For example, the first indoor unit 20 needs to be connected to the first outdoor pipe 181 through the first connection pipe 41, and the second indoor unit 30 needs to be connected to the second outdoor pipe 182 through the second connection pipe 42.

For example, the first connection valve 110 and the second connection valve 120 may be provided to be different in at least one of a shape, form, size, and color thereof. Since the first connection valve 110 and the second connection valve 120 are provided to be different from each other, mutual identification may be facilitated.

A mark for identifying the first connection valve 110 and the second connection valve 120 may be provided. For example, only one of the first connection valve 110 and the second connection valve 120 may be marked, or a mark formed on the first connection valve 110 and a mark formed on the second connection valve 120 may be provided to be different from each other. For example, only one of the first connection valve 110 and the second connection valve 120 may be subject to imprinting, or the imprint on the first connection valve 110 and the imprint of the second connection valve 120 may be different from each other.

A valve marker 170 for indicating a connection state of the first connection valve 110 and the second connection valve 120 may be provided. For example, the valve marker 170 may indicate that the first outdoor pipe 181 need to be connected to the first connection valve 110 and the second outdoor pipe 182 need to be connected to the second connection valve 120.

For example, the valve marker 170 may include a first valve marker 171 corresponding to the first connection valve 110 and may include a second valve marker 172 corresponding to the second connection valve 120. For example, the first valve marker 171 and the second valve marker 172 may include a lighting unit, such as a light emitting diode (LED), and the lighting unit of the first valve marker 171 and the lighting unit of the second valve marker 172 may be provided to present different colors.

However, it is not limited to the above-described examples, and various methods of identifying the first connection valve 110 and the second connection valve 120 may be adopted.

The third connection valve 130 and the fourth connection valve 140 maybe provided to be identifiable from each other. Similar to the first connection valve 110 and the second connection valve 120, various methods of mutually identifying the third connection valve 130 and the fourth connection valve 140 may be adopted.

With reference to FIG. 2 , an embodiment of an air conditioner 1 in which a plurality of first indoor units 20 and one second indoor unit 30 are connected to an outdoor unit 10 will be described. In FIG. 2 , the first indoor unit 20 is illustrated as two indoor units, but the disclosure is not limited thereto, and the first indoor unit 20 may be provided as two or more indoor units. The same reference numerals are assigned to the same configurations, and the same descriptions as those of FIG. 1 may be omitted.

Compared with the embodiment shown in FIG. 1 , the first indoor unit 20 may be provided in plural. Referring to FIG. 2 , the first indoor unit 20 may include a first a-indoor unit 20 a and a first b-indoor unit 20 b.

Each of the first outdoor pipe 181, the first connection valve 110, and the first connection pipe 41 may be provided in plural to correspond to the first indoor units 20. Each of the first outdoor pipe 181, the first connection valve 110, and the first connection pipe 41 may be provided corresponding in number to the number of the first indoor units 20.

For example, referring to FIG. 2 , the first outdoor pipe 181 may include a first a-outdoor pipe 181 a and a first-b outdoor pipe 181 b. The outdoor expansion valve 17 may include a first outdoor expansion valve 17 a disposed on the first a-outdoor pipe 181 a and a second outdoor expansion valve 17 b disposed on the first b-outdoor pipe 181 b. The first connection pipe 41 may include a first a-connection pipe 41 a and a first b-connection pipe 41 b. The first connection valve 110 may include a first a-connection valve 110 a and a first b-connection valve Hob.

The first outdoor pipes 181, the first connection valves 110, and the first connection pipes 41 may be respectively connected in series to form a plurality of refrigerant lines.

For example, the first a-outdoor pipe 181 a, the first a-connection valve 110 a, and the first a-connection pipe 41 a may form a first refrigerant line. For example, the first b-outdoor pipe 181 b, the first b-connection valve 110 b, and the first b-connection pipe 41 b may form a second refrigerant line.

Each of the first indoor units 20 may be connected to the outdoor heat exchanger 11 while corresponding to a respective one of the plurality of refrigerant lines. For example, the first a-indoor unit 20 a may be connected to the outdoor heat exchanger 11 through the first refrigerant line, and the first b-indoor unit 20 b may be connected to the outdoor heat exchanger 11 through the second refrigerant line.

Some portion of the refrigerant discharged from the outdoor heat exchanger 11 may flow into the first a-outdoor pipe 181 a and pass through the first outdoor expansion valve 17 a. The refrigerant discharged from the first a-outdoor pipe 181 a may pass through the first a-connection valve 110 a and the first a-connection pipe 41 a to be introduced into a first a-indoor heat exchanger 21 a.

Another portion of the refrigerant discharged from the outdoor heat exchanger 11 may flow into the first b-outdoor pipe 181 b and pass through the second outdoor expansion valve 17 b. The refrigerant discharged from the first b-outdoor pipe 181 b nay pass through the first b-connection valve 110 b and the first b-connection pipe 41 b to be introduced into a first b-indoor heat exchanger 21 b.

The remaining of the refrigerant discharged from the outdoor heat exchanger 11 may flow into the second outdoor pipe 182 and pass through the second connection valve 120 and the second connection pipe 42. The refrigerant passing through the second connection valve 120 and the second connection pipe 42 may pass through the indoor expansion valve 38 to be introduced into the second indoor heat exchanger 31.

Each of the third connection pipe 43, the third connection valve 130, and the third outdoor pipe 183 may also be provided in plural to correspond to the first indoor units 20. Each of the third connection pipe 43, the third connection valve 130, and the third outdoor pipe 183 may be provided corresponding in number to the number of the first indoor units 20.

For example, the third connection pipe 43 may include a third a-connection pipe 43 a and a third b-connection pipe 43 b. The third connection valve 130 may include a third a-connection valve 130 a and a third b-connection valve 130 b. The third outdoor pipe 183 may include a third-a outdoor pipe 183 a and a third b-outdoor pipe 183 b.

The first a-indoor unit 20 a, the third a-connection pipe 43 a, the third a-connection valve 130 a, and the third a-outdoor pipe 183 a may be connected in series. The first b-indoor unit 20 b, the third connection valve 43 b, the third b-connection valve 130 b, and the third b-outdoor pipe 183 b may be connected in series.

An embodiment of an air conditioner 1 in which one first indoor unit 20 and a plurality of second indoor units 30 are connected to an outdoor unit 10 will be described with reference to FIG. 3 . In FIG. 3 , the second indoor unit 30 is illustrated as two second indoor units, but the disclosure is not limited thereto, and the second indoor unit 30 may be provided as two or more second indoor units. The same reference numerals are assigned to the same configurations, and the same descriptions as those of FIGS. 1 and 2 may be omitted.

Compared with the embodiment shown in FIG. 1 , the second indoor unit 30 may be provided in plural. Referring to FIG. 3 , the second indoor unit 30 may include a second a-indoor unit 30 a and a second b-indoor unit 30 b, The second a-indoor unit 30 a may include a second a-indoor heat exchanger 31 a and a first indoor expansion valve 38 a. The second b-indoor unit 30 b may include a second b-indoor heat exchanger 31 b and a second indoor expansion valve 38 b.

The second connection pipe 42 may include one main connection pipe 421 provided to be connected to the second connection valve 120 and a plurality of sub connection pipes 422 a and 422 b branched from the main connection pipe 421. The plurality of sub connection pipes 422 a and 422 b may be provided to correspond to the plurality of second indoor units 30 a and 30 b, respectively. The plurality of sub connection pipes 422 a and 422 b may be provided corresponding in number to the number of the second indoor unit 30.

For example, referring to FIG. 3 , the plurality of sub connection pipes may include a first sub connection pipe 422 a connected to the second a-indoor unit 30 a and a second sub connection pipe 422 b connected to the second b-indoor unit 30 b.

Some portion of the refrigerant discharged from the outdoor heat exchanger 11 may flow into the first outdoor pipe 181 and pass through the outdoor expansion valve 17. The refrigerant discharged from the first outdoor pipe 181 may pass through the first connection valve 110 and the first connection pipe 41 to be introduced into the first indoor heat exchanger 21.

The remaining of the refrigerant discharged from the outdoor heat exchanger 11 may flow into the second outdoor pipe 182 and pass through the second connection valve 120. The refrigerant discharged from the second connection valve 120 may flow through the main connection pipe 421 and branch through the sub connection pipes 422 a and 422 b.

The refrigerant flowing into the first sub-connection pipe 422 a may pass through the first indoor expansion valve 38 a and flow into the second a-indoor heat exchanger 31 a. The refrigerant flowing into the second sub connection pipe 422 b may pass through the second indoor expansion valve 38 b and flow into the second b-indoor heat exchanger 31 b.

The fourth connection pipe 44 may include a plurality of sub connection pipes 442 a and 442 b connected to the plurality of second indoor units 30 a and 30 b, respectively, and a main connection pipe 441 in which the plurality of sub connection pipes 442 a and 442 b join. The main connection pipe 441 may be connected to the fourth connection valve 140.

The refrigerants discharged from the plurality of second indoor units 30 a and 30 b may flow along the respective sub-connection pipes 442 a and 442 b. The refrigerants flowing through the respective sub-connection pipes 442 a and 442 b may join in the main connection pipe 441. The refrigerant joining in the main connection pipe 441 may pass through the fourth connection valve 140 and flow into the fourth outdoor pipe 184.

With reference to FIG. 4 , an embodiment of an air conditioner 1 in which a plurality of first indoor units 20 and a plurality of second indoor units 30 are connected to an outdoor unit 10 will be described. In FIG. 4 , the first indoor unit 20 is illustrated as two first indoor units 20 and the second indoor unit 30 is illustrated as two second indoor units 30, but the disclosure is not limited thereto. The first indoor unit 20 may be provided as two or more first indoor units 20, and the second indoor unit 30 may be provided as two or more second indoor units 30. The same reference numerals are assigned to the same configurations, and the same descriptions as those of FIGS. 1 to 3 may be omitted.

Referring to FIG. 4 , the outdoor unit 10 may be connected to the plurality of first indoor units 20 and the plurality of second indoor units 30. The air conditioner 1 may be provided in a structure in which a multi-pipe structure and a single-pipe structure are integrated.

For example, the first a-outdoor pipe 181 a, the first a-connection valve 110 a, the first a-connection pipe 41 a, and the first a-indoor unit 20 a may be connected in series. The first b-outdoor pipe 181 b, the first b-connection valve 110 b, the first b-connection pipe 41 b, and the first b-indoor unit 20 b may be connected in series. The first a-indoor unit 20 a, the third a-connection pipe 43 a, the third a-connection valve 130 a, and the third a-outdoor pipe 183 a may be connected in series. The first b-indoor unit 20 b, the third connection pipe 43 b, the third b-connection valve 130 b, and the third b-outdoor pipe 183 b may be connected in series. That is, with such a connection, a multi-pipe structure may be provided.

For example, the sub connection pipe 422 a, the second a-indoor unit 30 a, and the sub connection pipe 442 a may be connected in series (hereinafter, referred to as a first connection part). The sub connection pipe 422 b, the second b-indoor unit 30 b, and the sub connection pipe 442 b may be connected in series (hereinafter, referred to as a second connection part). The first connection part and the second connection part may be connected in parallel to each other. That is, the plurality of sub connection pipes 422 a and 422 b branched from the main connection pipe 421 are connected to the plurality of second indoor units 30 a and 30 b, respectively, and the plurality of sub connection pipes 442 a and 442 b extending from the plurality of second indoor units 30 a and 30 b may join at the main connection pipe 441. That is, with such a connection, a single pipe structure may be provided.

The first indoor units 20 a and 20 b not provided with an indoor expansion valve may be respectively connected to the first outdoor pipes 181 a and 181 b in which the outdoor expansion valves 17 a and 17 b are disposed. The second indoor units 30 a and 30 b provided with the indoor expansion valves may be connected to the second outdoor pipe 182 in which the outdoor expansion valves 17 a and 17 b are not disposed. For example, the second indoor units 30 a and 30 b may be connected to the second outdoor pipe 182 through the branch pipes 422 a and 422 b, respectively.

As described above, the air conditioner 1 may be provided in a structure in which a multi-pipe structure and a single-pipe structure are integrated. Accordingly, the indoor units 20 and 30 may be connected to the outdoor unit 10 regardless of whether the indoor unit has an expansion valve built-in. In addition, since a separate distribution device is not required, the piping design is simplified, which is beneficial in space securing.

FIG. 5 is a diagram schematically illustrating a cooling operation mode of the air conditioner shown in FIG. 1 .

Referring to FIG. 5 , in a cooling operation mode, a refrigerant may be circulated in the order of the compressor 15, the four-way valve 16, the outdoor heat exchanger 11, and the indoor units 20 and 30. In this case, the outdoor heat exchanger 11 may serve as a condenser, and the first indoor heat exchanger 21 and the second indoor heat exchanger 22 may serve as an evaporator.

The four-way valve 16 may connect the first port 161 to the third port 163 and connect the second port 162 to the fourth port 164.

The refrigerant compressed in the compressor 15 may be introduced into the outdoor heat exchanger 11 by the four-way valve 16. The refrigerant heat-exchanged with outdoor air in the outdoor heat exchanger 11 may flow toward the indoor units 20 and 30.

The refrigerant discharged from the outdoor heat exchanger 11 may be branched through the first outdoor pipe 181 and the second outdoor pipe 182.

The refrigerant flowing into the first outdoor pipe 181 may pass through the outdoor expansion valve 17. The refrigerant passing through the outdoor expansion valve 17 may pass through the first connection valve 110 and the first connection pipe 41 to be introduced into the first indoor heat exchanger 21. The refrigerant heat-exchanged with the indoor air in the first indoor heat exchanger 21 may pass through the third connection pipe 43 and the third connection valve 130 to be introduced into the four-way valve 16. The refrigerant passed through the four-way valve 16 may be introduced back into the compressor 15.

The refrigerant introduced into the second outdoor pipe 182 may bypass the outdoor expansion valve 17. The refrigerant bypassing the outdoor expansion valve 17 may pass through the second connection valve 120 and the second connection pipe 42 to flow into the indoor expansion valve 38. The refrigerant expanded under reduced pressure in the indoor expansion valve 38 may be introduced into the second indoor heat exchanger 31. The refrigerant heat-exchanged with the indoor air in the second indoor heat exchanger 31 may pass through the fourth connection pipe 44 and the fourth connection valve 140 and then flow into the four-way valve 16. The refrigerant passed through the four-way valve 16 may be introduced back into the compressor 15.

FIG. 6 is a diagram schematically illustrating a heating operation mode of the air conditioner shown in FIG. 1 .

Referring to FIG. 6 , in a heating operation mode, the refrigerant may be circulated in the order of the compressor 15, the four-way valve 16, the indoor units 20 and 30, and the outdoor heat exchanger 11. In this case, the outdoor heat exchanger 11 may serve as an evaporator, and the first indoor heat exchanger 21 and the second indoor heat exchanger 31 may serve as a condenser.

The four-way valve 16 may connect the first port 161 to the fourth port 164 and connect the second port 162 to the third port 163.

The refrigerant compressed in the compressor 15 may be caused to flow toward the indoor units 20 and 30 by the four-way valve 16.

The refrigerant discharged from the four-way valve 16 may be branched through the third outdoor pipe 183 and the fourth outdoor pipe 184.

The refrigerant introduced into the third outdoor pipe 183 may pass through the third connection valve 130 and the third connection pipe 43 to be introduced into the first indoor heat exchanger 21. The refrigerant heat-exchanged with indoor air in the first indoor heat exchanger 21 may pass through the first connection pipe 41 and the first connection valve 110 and flow into the first outdoor pipe 181. The refrigerant flowing into the first outdoor pipe 181 may pass through the outdoor expansion valve 17 to be introduced into the outdoor heat exchanger 11. The refrigerant heat-exchanged with outdoor air in the outdoor heat exchanger 11 may be introduced back into the compressor 15 by the four-way valve 16.

The refrigerant flowing into the fourth outdoor pipe 184 may pass through the fourth connection valve 140 and the fourth connection pipe 44 to be introduced into the second indoor heat exchanger 31. The refrigerant heat-exchanged with indoor air in the second indoor heat exchanger 31 may pass through the indoor expansion valve 38 of the second indoor unit 20. The refrigerant passed through the indoor expansion valve 38 may pass through the second connection pipe 42 and the second connection valve 120 to be introduced into the second outdoor pipe 182. The refrigerant introduced into the second outdoor pipe 182 may be introduced into the outdoor heat exchanger 11. The refrigerant heat-exchanged with outdoor air in the outdoor heat exchanger 11 may be introduced back into the compressor 15 by the four-way valve 16.

FIG. 7 is a control block diagram illustrating an air conditioner according to an embodiment.

Referring to FIG. 7 , the air conditioner 1 may include controllers 100, 200, and 300 for controlling each component of the air conditioner 1. For example, the outdoor unit 10 may include an outdoor unit controller 100, the first indoor unit 20 may include a first indoor unit controller 200, and the second indoor unit 30 may include a second indoor unit controller 300. However, the disclosure is not limited thereto, and the outdoor unit controller 100, the first indoor unit controller 200, and the second indoor unit controller 300 may be integrated into one body. For example, some of the outdoor unit controller 100, the first indoor unit controller 200, and the second indoor unit controller 300 may be integrated into one body.

The outdoor unit controller 100 may control the operation of the outdoor unit 10. The outdoor unit controller 100 may receive various types of information about the operation of the outdoor unit 10, and control components of the outdoor unit 10 based on the received information. For example, the outdoor unit controller 100 may control the operation of the compressor 15, the accumulator 14, the fan motor 12, the outdoor fan 13, the four-way valve 16, the outdoor expansion valve 17, and the like.

The outdoor unit controller 100 may control the opening degree of the first connection valve 110, the second connection valve 120, the third connection valve 130, and the fourth connection valve 140 to adjust the amount of refrigerant flowing in or flowing out of the indoor units 20 and 30.

The outdoor unit controller 100 may control the valve marker 170. The outdoor unit controller 100 may control the valve marker 170 so that the first connection valve 110 and the second connection valve 120 are mutually identified from each other. For example, the first valve marker 171 corresponding to the first connection valve 110 and the second valve marker 171 corresponding to the second connection valve 120 may be provided in different forms to be identified from each other.

Meanwhile, the outdoor unit controller 100 may control the third connection valve 130 and the fourth connection valve 140 to be mutually identified from each other. Although not shown in the drawing, the valve marker 170 may include a third valve marker (not shown) corresponding to the third connection valve 130 and a fourth valve marker (not shown) corresponding to the fourth connection valve 140. In this case, the outdoor unit controller 100 may control the operations of the third valve marker and the fourth valve marker.

The outdoor unit 100 may further include an outdoor unit communicator 150. The outdoor unit communicator 150 may be connected to the outdoor unit controller 100 and provided to communicate with the indoor units 20 and 30. For example, the outdoor unit communicator 150 may be provided to communicate with a first indoor unit communicator 230 and a second indoor unit communicator 330. For example, the outdoor unit communicator 150 may be provided to communicate with a user terminal (e.g., a mobile phone, a tablet, a personal computer (PC), etc.).

The outdoor unit communicator 150 may receive information on whether the indoor units 20 and 30 include an indoor expansion valve. For example, the outdoor unit communicator 150 may receive, from the first indoor unit communicator 230, information about inclusion of an indoor expansion valve. The outdoor unit communicator 150 may receive, from the second indoor unit communicator 330, information about inclusion of the indoor expansion valve 38.

The outdoor unit controller 100 may be provided to control the valve marker 170 based on information received from the outdoor unit communicator 150. For example, when the second indoor unit 30 is connected to the first connection valve 110 and the first indoor unit 20 is connected to the second connection valve 120, the air conditioner 1 may inform the user that the pipe connection is incorrect through various methods (e.g., a warning sound, a LED lighting, etc.). In addition, when the second indoor unit 30 is connected to the third connection valve 130 and the first indoor unit 20 is connected to the fourth connection valve 140, the air conditioner 1 may inform the user that the pipe connection is incorrect using various methods (e.g., a warning sound, a LED lighting, etc.).

The first indoor unit controller 200 may control the operation of the first indoor unit 20. The first indoor unit controller 200 may control components of the first indoor unit 20. For example, the first indoor unit controller 200 may control operations of the fan motor 22, the indoor fan 23, and the connection valves 26 and 27.

The first indoor unit controller 200 may control the opening degrees of the connection valves 26 and 27 to adjust the amount of refrigerant flowing in or flowing out of the outdoor unit 10.

The first indoor unit 20 may include an inputter 210, a display 220, and a first indoor unit communicator 230.

The inputter 210 may be provided to receive information from a user. The display 220 may display the operating state of the first indoor unit 20. The inputter 210 and the display 220 may be provided separately, or may be integrated into one body and provided as a user interface (at UI). The inputter 210 and the display 220 may be connected to the first indoor unit controller 200.

The first indoor unit communicator 230 may be connected to the first indoor unit controller 200 and provided to communicate with the outdoor unit communicator 150. For example, the first indoor unit communicator 230 may transmit, to the outdoor unit communicator 150, information on whether the first indoor unit 20 includes an indoor expansion valve.

The second indoor unit controller 300 may control the operation of the second indoor unit 30. The second indoor unit controller 300 may control components of the second indoor unit 30. For example, the second indoor unit controller 300 may control operations of the fan motor 32, the indoor fan 33, the connection valves 36 and 37, and the indoor expansion valve 38.

The second indoor unit controller 300 may control the opening degrees of the connection valves 36 and 37 to adjust the amount of refrigerant flowing in or flowing out of the outdoor unit 10.

The second indoor unit 30 may include an inputter 310, a display 320, and a second indoor unit communicator 330.

The inputter 310 may be provided to receive information from a user. The display 320 may display the operating state of the second indoor unit 30. The inputter 310 and the display 320 may be provided separately, or may be integrated into one body and provided as a user interface (an UI). The inputter 310 and the display 320 may be connected to the second indoor unit controller 300.

The second indoor unit communicator 330 may be connected to the second indoor unit controller 300 and provided to communicate with the outdoor unit communicator 150, For example, the first indoor unit communicator 330 may transmit, to the outdoor unit communicator 150, information on whether the second indoor unit 30 includes the indoor expansion valve 38.

One aspect of the disclosure provides an air conditioner having an improved refrigerant pipe structure.

Another aspect of the disclosure provides an air conditioner including an outdoor unit connectable to both an indoor unit having an expansion valve built-in and an indoor unit not having an expansion valve built-in.

Another aspect of the disclosure provides an air conditioner capable of implementing both a single pipe structure and a multi-pipe structure.

According to one aspect of the disclosure, the air conditioner can easily connect an indoor unit to are outdoor unit regardless of whether an expansion valve is included in the indoor unit.

According to one aspect of the disclosure, the air conditioner can combine a single pipe structure and a multi-pipe structure.

According to one aspect of the disclosure, the air conditioner can easily install an indoor unit without a separate distribution device.

Although certain illustrative embodiments and implementations have been described herein, other embodiments and modifications will be apparent from this description. Accordingly, the inventive concepts are not limited to such embodiments, but rather to the broader scope of the appended claims and various obvious modifications and equivalent arrangements as would be apparent to a person of ordinary skill in the art. 

What is claimed is:
 1. An air conditioner comprising: an outdoor unit including a compressor and an outdoor heat exchanger; a first indoor unit including a first indoor heat exchanger; and a second indoor unit including a second indoor heat exchanger and an indoor expansion valve, wherein the outdoor unit includes: an outdoor expansion valve; a first outdoor pipe provided with the outdoor expansion valve, the first outdoor pipe allowing a refrigerant discharged from the outdoor heat exchanger to pass through the outdoor expansion valve and flow to the first indoor unit; and a second outdoor pipe allowing a refrigerant discharged from the outdoor heat exchanger to bypass the outdoor expansion valve and flow to the second indoor unit.
 2. The air conditioner of claim 1, further comprising: a first connection pipe connecting the outdoor unit to the first indoor unit by connecting to the first outdoor pipe of the outdoor unit; and a second connection pipe connecting the outdoor unit to the second indoor unit by connecting to the second outdoor pipe of the outdoor unit.
 3. The air conditioner of claim 2, wherein the outdoor unit further comprises: a first connection valve connecting the first outdoor pipe to the first connection pipe; and a second connection valve connecting the second outdoor pipe to the second connection pipe.
 4. The air conditioner of claim 3, wherein the refrigerant passing through the outdoor expansion valve is to pass through the first connection valve and the first connection pipe and then flow into the first indoor heat exchanger, and the refrigerant bypassing the outdoor expansion valve is to pass through the second connection valve and the second connection pipe and then flow into the indoor expansion valve.
 5. The air conditioner of claim 3, further comprising: a plurality of first indoor units, the plurality of first indoor units including the first indoor unit; a plurality of first outdoor pipes, the plurality of first outdoor pipes including the first outdoor pipe; a plurality of first connection valves, the plurality of first connection valves including the first connection valve; and a plurality of first connection pipes, the plurality of first connection pipes including the first connection pipe, the plurality of first outdoor pipes, the plurality of first connection valves, and the plurality of first connection pipes are respectively connected in series to form a plurality of refrigerant lines, and each of the plurality of first indoor units corresponds to a respective one of the plurality of refrigerant lines to be connected to the outdoor heat exchanger.
 6. The air conditioner of claim 3, further comprising a plurality of second indoor units, the plurality of second indoor units including the second indoor unit, and the second connection pipe includes: a main connection pipe to be connected to the second connection valve; and a plurality of sub connection pipes branched from the main connection pipe and each of the plurality of sub connection pipes corresponding to a respective one of the plurality of second indoor units.
 7. The air conditioner of claim 3, wherein the first connection valve has at least one of a shape, a form, a size, and a color different from those of the second connection valve so that the first connection valve and the second connection valve are visually identifiable from each other.
 8. The air conditioner of claim 7, wherein the outdoor unit further comprises a valve marker configured to indicate a connection state of the first connection valve and the second connection valve.
 9. The air conditioner of claim 8, wherein the outdoor unit further comprises an outdoor unit communicator to communicate with the first indoor unit and the second indoor unit, the outdoor unit communicator configured to receive information on whether the first indoor unit includes an indoor expansion valve and information on whether the second indoor unit includes an indoor expansion valve.
 10. The air conditioner of claim 9, further comprising a controller configured to control the valve marker based on the information received from the outdoor unit communicator.
 11. The air conditioner of claim 1, further comprising: a third connection pipe connecting the first indoor unit to the outdoor unit such that a refrigerant discharged from the first indoor unit is introduced into the outdoor unit; and a fourth connection pipe connecting the second indoor unit to the outdoor unit such that a refrigerant discharged from the second indoor unit is introduced into the outdoor unit.
 12. The air conditioner of claim 11, wherein the outdoor unit further comprises: a third outdoor pipe through which the refrigerant flowing through the third connection pipe is introduced; and a fourth outdoor pipe through which the refrigerant flowing through the fourth connection pipe is introduced, wherein the third outdoor pipe and the fourth outdoor pipe are provided to join before being introduced into the compressor.
 13. The air conditioner of claim 12, wherein the outdoor unit further comprises: a third connection valve connecting the third outdoor pipe to the third connection pipe; and a fourth connection valve connecting the fourth outdoor pipe to the fourth connection pipe.
 14. The air conditioner of claim 13, wherein the third connection valve has at least one of a shape, a form, a size, and a color different from those of the fourth connection valve so that the third connection valve and the fourth connection valve are visually identifiable from each other.
 15. The air conditioner of claim 1, further comprising a four-way valve configured to switch a flow path such that a refrigerant compressed by the compressor selectively flows to the outdoor heat exchanger or to the first indoor heat exchanger and the second indoor heat exchanger. 